const mongoose = require('mongoose')
mongoose.connect('mongodb://localhost:27017/test', {
  useNewUrlParser: true,
  useUnifiedTopology: true
})
const db = mongoose.connection
db.on('error', console.error.bind(console, 'connection error: '))
db.once('open', function () {
  console.log("数据库成功连接")
})
module.exports = db